Method and apparatus for dampening and filtering air flow effects in a hard disk drive

ABSTRACT

A hard disk drive is disclosed including at least one air filter mounted on a shroud wall of the base and at least two disk dampers where at least one disk damper covers a fraction of the maximal covering angle configured with the air filter to optimize both the air filter and disk dampening. Methods of manufacturing the hard disk drive are also disclosed.

TECHNICAL FIELD

This invention relates to hard disk drives including at least one air filter and at least two disk dampers.

BACKGROUND OF THE INVENTION

For several years, it has been common practice for hard disk drives to incorporate disk dampers near the surfaces of disks to reduce of vibration from the wind off the rotating disk surfaces. The general rule of thumb has been that the disk dampers should cover a maximum of the disk surfaces to minimize the vibration effects, known herein as disk flutter suppression. It has also been common to include air filters in hard disk drives. However, it has not been generally known that these components can be optimized together to achieve better performance in new configurations for the hard disk drive.

SUMMARY OF THE INVENTION

One embodiment of the invention include a hard disk drive with at least one air filter mounted on a shroud wall of a base and at least two disk dampers where at least one of the disk dampers covers a fraction of the maximal covering angle configured with the air filter to optimize performance for both the air filter and the disk dampers. Such embodiments may have improved filtration performance with similar damping effect on wind-induced vibration when compared to a hard disk drive where all the disk dampers have the maximal covering angle. As used herein the covering angle is measured about the center of the disks and is the angle that the disk damper covers over at least one disk surface. The covering angle may further optimize power consumption.

The hard disk drive operates through the wind entering the intake and the second intake providing suction to pull the wind through the air filter to create filtered air sent through an outlet channel back into the disk cavity, which is optimized by the top disk damper being smaller than the bottom disk damper without appreciable decline in disk flutter suppression. When a third disk damper is present between the top and bottom dampers, it is smaller than the bottom and larger that the top disk damper and further aids the performance of the air filter.

Another embodiment of the hard disk drive includes the disk dampers in the opposite order, with the top disk damper having a larger covering angle the one below it and so on.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example embodiment of a hard disk drive that includes a base includes a shroud wall including an air filter between an intake and a second intake. A spindle motor is mounted on the base and is coupled to rotate multiple disks in the disk cavity formed by the shroud wall. A wind is generated off a rotating disk surface as the spindle motor rotates the disks. The hard disk drive includes three disk dampers separating the disks, with a top disk damper, a bottom disk damper and a third disk damper between the top and bottom disk dampers. The covering angle of the top disk damper is less than the covering angle of the third disk damper, which is less than the maximal covering angle of the bottom disk damper. The hard disk drive operates through the wind entering the intake and the second intake providing suction to pull the wind through the air filter to create filtered air sent through an outlet channel back into the disk cavity, which is optimized by the top disk damper being smaller than the bottom disk damper without appreciable decline in disk flutter suppression.

FIG. 2 shows a partial cross section view is the cross section of an example of the hard disk drive of FIG. 1, showing the top and bottom disk damper, the intake, the second intake and the outlet in use with two disks.

FIGS. 3 and 4 show partial cross section views of examples of the hard disk drive of FIG. 1, showing the three disk dampers, the intake, the second intake and the outlet in use with three disks.

FIG. 5 shows another example embodiment as a variant of FIG. 3, including the disk dampers in the opposite order, with the top disk damper having a larger covering angle the one below it and so on.

DETAILED DESCRIPTION

This invention relates to hard disk drives including at least one air filter and at least two disk dampers. Embodiments of the invention include a hard disk drive with at least one air filter mounted on a shroud wall of a base and at least two disk dampers where at least one of the disk dampers covers a fraction of the maximal covering angle configured with the air filter to optimize both the air filter and disk dampening. Such embodiments may have improved filtration performance with similar damping effect on wind-induced vibration, or disk flutter suppression, when compared to a hard disk drive where all the disk dampers have the maximal covering angle. As used herein the covering angle is measured about the center of the disks and is the angle that the disk damper covers over at least one disk surface.

Referring to the drawings more particularly by reference numbers, FIG. 1 shows an example embodiment of a hard disk drive 10 that includes a base 16 that includes a shroud wall 82 including an air filter 110 between an intake 100 and a second intake 104. A spindle motor 14 is mounted on the base and is coupled to rotate multiple disks 12 in the disk cavity formed by the shroud wall. A wind is generated off a rotating disk surface 6 as the spindle motor rotates the disks. The hard disk drive includes three disk dampers separating the disks, with a top disk damper 90, a bottom disk damper 94 and a third disk damper 92 between the top and bottom disk dampers. The covering angle 98 of the top disk damper is less than the covering angle 93 of the third disk damper, which is less than the maximal covering angle 96 of the bottom disk damper.

The hard disk drive 10 operates through the wind entering the intake 100 and the second intake 104 providing suction to pull the wind through the air filter 110 to create filtered air sent through an outlet channel 102 back into the disk cavity, which is optimized by the top disk damper 90 being smaller than the bottom disk damper 94 without appreciable decline in disk flutter suppression. The suction is often referred to as the Bernoulli effect. When a third disk damper 92 is present between the top and bottom dampers, it is preferably smaller than the bottom and larger that the top disk damper and further aids the performance of the air filter based upon extensive simulation analyses.

Embodiments of the invention include at least one air filter 110 mounted on the shroud wall 82 of the base 16 and at least two disk dampers where at least one of the disk dampers covers a fraction of the maximal covering angle 94 configured with the air filter to optimize both the air filter and disk dampening. Such embodiments may have improved filtration performance with similar damping effect on wind-induced vibration when compared to a hard disk drive where all the disk dampers have the maximal covering angle. As used herein the covering angle is measured about the center of the disks 12 and is the angle that the disk damper covers over at least one disk surface 6.

A voice coil motor 36 is mounted to the base 16 and includes at least one actuator arm for pivoting a head gimbal assembly 26 to position a slider 20 near a track on the rotating disk surface 6, all of which is affected by the air flow resulting from the configuration of air filter 110, the disk dampers 90, 92 and 94, the shroud wall 82, and the rotating disk surfaces. The voice coil motor pivots about the actuator pivot 30, moving in response to electrical stimulus the voice coil 32 and its interaction with a fixed magnet assembly 34. A disk cover 18 is mounted upon the base to encapsulate all of the shown components except the control circuit 40, which is usually mounted on the opposite side of the base.

By way of example, FIGS. 2 to 5 shows embodiments of the hard disk drive 10 of FIG. 1 seen in partial cross section. FIG. 2 shows the hard disk drive including two disks 12, two disk dampers, in particular, the top damper 90 and the bottom damper 94, with the intake 100, the second intake 104, and the outlet 102 formed on the shroud wall 82.

FIGS. 3 to 5 further show the hard disk drive 10 including three disks and a third disk damper 92 having a covering angle between the top disk damper 90 and the bottom disk damper 92. FIG. 3 shows the covering angle of the middle disk damp as less than the bottom disk damper as shown in FIG. 1, whereas FIG. 4 shows the middle disk damper having essentially the same covering angle as the bottom disk damper. FIG. 5 shows the embodiment of the hard disk drive with the opposite order to the disk dampers, with covering angle of the bottom disk damper less than the middle disk damper, which is less than the covering angle of the top disk damper.

The preceding embodiments provide examples of the invention, and are not meant to constrain the scope of the following claims. 

1. A hard disk drive, comprising: a base including a shroud wall further including an air filter; a spindle motor mounted on said base and rotatably coupled to at least two disks; a bottom disk damper mounted to said shroud wall between a first of said disks and a second of said disks covering said disks at a bottom covering angle of at most a maximal covering angle; and a top disk damper mounted to said shroud wall covering one of said disks at top covering angle that is at most N percent of said maximal covering angle, with said N at most eighty, said air chamber is located at a chamber angle of at least N percent of said maximal covering angle, and said top covering angle is at most said bottom covering angle.
 2. The hard disk drive of claim 1, wherein said shroud wall further includes a chamber including said air filter.
 3. The hard disk drive of claim 2, wherein said shroud wall further includes a second of said chambers.
 4. The hard disk drive of claim 1, wherein said spindle motor is rotatably coupled to at least three of said disks; said hard disk drive further comprises a third of said disk dampers mounted between said second of said disks and a third of said disks and covering said second of said disks by a third of said covering angles that is about M percent of said maximal covering angle, with said M not less than said N.
 5. The hard disk drive of claim 4, wherein said N is at least thirty and said M is at least fifty.
 6. The hard disk drive of claim 4, wherein said chamber angle is at least said M percent of said maximal covering angle.
 7. The hard disk drive of claim 4, wherein said chamber angle is at most said M percent of said maximal covering angle.
 8. The hard disk drive of claim 1, wherein said bottom covering angle is essentially said maximal covering angle.
 9. A hard disk drive, comprising: a base including a shroud wall further including an air filter; a spindle motor mounted on said base and rotatably coupled to at least two disks; a top disk damper mounted to said shroud wall between a first of said disks and a second of said disks at essentially a maximal covering angle; and a bottom disk damper mounted to said shroud wall covering one of said disks at bottom covering angle that is at most N percent of said maximal covering angle, with said N at most eighty, and said air chamber is located at a chamber angle of at least N percent of said maximal covering angle.
 10. The hard disk drive of claim 9, wherein said shroud wall further includes a chamber including said air filter.
 11. The hard disk drive of claim 10, wherein said shroud wall further includes a second of said chambers.
 12. The hard disk drive of claim 9, wherein said spindle motor is rotatably coupled to at least three of said disks; said hard disk drive further comprises a third of said disk dampers mounted between said second of said disks and a third of said disks and covering said second of said disks by a third of said covering angles that is about M percent of said maximal covering angle, with said M not less than said N.
 13. The hard disk drive of claim 12, wherein said N is at least thirty and said M is at least fifty.
 14. The hard disk drive of claim 12, wherein said chamber angle is at least said M percent of said maximal covering angle.
 15. The hard disk drive of claim 12, wherein said chamber angle is at most said M percent of said maximal covering angle.
 16. The hard disk drive of claim 9, wherein said top covering angle is essentially said maximal covering angle.
 17. A method of manufacturing a hard disk drive, comprising the steps of: providing a base including a shroud wall including an air filter; assembling at least two disk dampers between at least two disks rotating coupled to a spindle motor; and mounting said spindle motor and said disk dampers to said base to at least partly create said hard disk drive with a top of said disk dampers mounted to said shroud wall between a first of said disks and a second of said disks at a top covering angle at most a maximal covering angle, and with a bottom of said disk dampers mounted to said shroud wall covering one of said disks at a bottom covering angle at most said maximal covering angle; wherein at least one member of a covering angle group is at most N percent of said maximal covering angle, with said N at most eighty, said covering angle group consisting of said bottom covering angle and said top covering angle. 